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v0.5.1
https://github.com/python/cpython
09 December 2020, 11:06:31 UTC
Revision b90c68586e1f2c45c736dd38880f182be267e2ef authored by Miss Islington (bot) on 06 February 2018, 06:51:10 UTC, committed by Gregory P. Smith on 06 February 2018, 06:51:10 UTC 
bpo-32777: Fix _Py_set_inheritable async-safety in subprocess (GH-5560) (GH-5563)
 
Fix a rare but potential pre-exec child process deadlock in subprocess on POSIX systems when marking file descriptors inheritable on exec in the child process.  This bug appears to have been introduced in 3.4 with the inheritable file descriptors support.

This also changes Python/fileutils.c `set_inheritable` to use the "slow" two `fcntl` syscall path instead of the "fast" single `ioctl` syscall path when asked to be async signal safe (by way of being asked not to raise exceptions).  `ioctl` is not a POSIX async-signal-safe approved function.

ref: http://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html
(cherry picked from commit c1e46e94de38a92f98736af9a42d89c3975a9919)

Co-authored-by: Alexey Izbyshev <izbyshev@users.noreply.github.com>
1 parent 7bd5a75
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Tip revision: b90c68586e1f2c45c736dd38880f182be267e2ef authored by Miss Islington (bot) on 06 February 2018, 06:51:10 UTC
bpo-32777: Fix _Py_set_inheritable async-safety in subprocess (GH-5560) (GH-5563)
Tip revision: b90c685
node.h 

/* Parse tree node interface */

#ifndef Py_NODE_H
#define Py_NODE_H
#ifdef __cplusplus
extern "C" {
#endif

typedef struct _node {
    short		n_type;
    char		*n_str;
    int			n_lineno;
    int			n_col_offset;
    int			n_nchildren;
    struct _node	*n_child;
} node;

PyAPI_FUNC(node *) PyNode_New(int type);
PyAPI_FUNC(int) PyNode_AddChild(node *n, int type,
                                      char *str, int lineno, int col_offset);
PyAPI_FUNC(void) PyNode_Free(node *n);
#ifndef Py_LIMITED_API
PyAPI_FUNC(Py_ssize_t) _PyNode_SizeOf(node *n);
#endif

/* Node access functions */
#define NCH(n)		((n)->n_nchildren)

#define CHILD(n, i)	(&(n)->n_child[i])
#define RCHILD(n, i)	(CHILD(n, NCH(n) + i))
#define TYPE(n)		((n)->n_type)
#define STR(n)		((n)->n_str)
#define LINENO(n)       ((n)->n_lineno)

/* Assert that the type of a node is what we expect */
#define REQ(n, type) assert(TYPE(n) == (type))

PyAPI_FUNC(void) PyNode_ListTree(node *);

#ifdef __cplusplus
}
#endif
#endif /* !Py_NODE_H */
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